I am trying to write an article on the musician Susumu Hirasawa. He's credited for writing two pieces on the X-Bomber OST. While the OST is credited to Bow Wow & E-Project, the series opening credits name Bow Wow, Kazutaka Tazaki of The Bach Revolution and Nakayuki Sakuraba for music.

The wiki page for the OST says that most of the pieces weren't used in the series. What I need to know is, do track 9 & 10 of the OST appear in the series proper?

If anybody here's interested in learning more about The Bach Revolution and/or Hirasawa I'll gladly reply.

No need, I've got an answer for you. I'll give you all the instances I know of.

Track 1 - Obviously the intro theme
Track 2 - The first part is used in Episode 7 when X-Bomber comes out of the Black Hole and the latter part of it used a few other time (but I don't think it had the drum beats). The second part is used quite a few times basically a threatening sounding Alliance theme, also first used in Episode 7. The ending part I don't recall being used.
Track 3 - First used in Episode 9. This is The Imperial Masters theme.
Track 4 - First used in Episode 18, and at the end of Episode 21 (Episode 20 - UK). It was also used in the "X-Bomber" Preview show during the Imperial attack on Pluto Alpha Base, though was not used in the final Episode.
Track 5 - Used quite a few times.
Track 6 - Never used, which is a shame because it's an awesome theme
Track 7 - Another gloomy theme used a lot on the series, usually at the beginning or end of an episode.
Track 8 - Used a couple of times. The main time that comes to mind is when the Dai-X fighters launch from X-Bomber on Pluto on Episode 5
Track 9 - The Beginning Part was never used in the series, but the second part was used. It is used the first time we see Lamia, and is pretty much used as her main theme.
Track 10 - Was never used.
Track 11 - The Astro fighter Theme. Used as The Pluto Astro fighters are launched from Pluto Base to be blown up by Makara's cruiser.
Track 12 - Never used
Track 13 - Never used
Track 14 - The theme used as the lads are preparing to launch Dai-X
Track 15 - Never used
Track 16 - A theme I usually call Lamia's Second theme. It is first used in Episode 5 when the lads try to convince Lamia to return to X-Bomber.
Track 17 - The Ending theme

Another thing about crediting: Do the liner notes credit Tazaki & Sakuraba? As far as I know neither man was part of either Bow Wow or E-Project (Tazaki maybe, info about E-Project is hard to come by) & it's kinda weird that 3 guys got shafted credit-wise. Also, do any of the tracks have "rock" instruments? Bow Wow get top billing on the OST but I think they're only on the opening & ending.